Psogess



R. L. SMITH.

LEATHER FINISHING PROCESS.

APPLICATION FILED MAY 2. 19H.

1 ,3 1 1 ,1 88'. Patented July 29, 1919. Fig.1.

Fig.3.

' however, is of. a broader nature LEATHER-FINISHING PROCESS.

Specification-of Letters Patent.

Patented July 29, 1919,

Application filed May 2, 1917. Serial No. 166,004.

7 '0 all whom it may concern:

Be it known that I, ROLAND L. SMITH, a citizen of the United States, and resident of Everett, county of Middlesex, State of ,Massachusetts, have invented an Improvement in Leather-Finishing Processes, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to improvements in leather finishing processes and relates more particularly to providing a novel process for refinishing enamel or patent leather in which the enamel has become marred, scratched, broken or otherwise injured. The invention, and is also adapted for the treatment of leater to produce a lustrous finish similar to that of enamel or patent leather.

Leathers such as are leather, enamel leather, rjapanned leather and the like, which present a lustrous surface are formed by applying one, or usually several coatings of :a composition having varnish-like properties to a leather or fibrous base and finally bakingthe same at a moderate temperature for a considerable period of time.

In handling such leathers in the manufacture of various articles, and particularly shoes, the enameled surface of the leather frequently becomes. marred, scratched or more often cracked and heretofore great difficulty has been experienced in refinishing the leather to remove the defects caused by the mars, scratches or cracks. This has usually been done by first scraping off the enamel down to the deepest part of the cracks and then applying-t0 the crack or to the marred surface a varnish-like filling composition containing a. volatile solvent until substantially the same finish appears as that known as patent of the body of the leather.

It has been however quite impossible heretofore to produce the same luster upon the filled in part as that of the original surface for the reason that the filler itself or the filler when varnished, presents a somewhat uneven painted, 0r glazed surface which has a higher polish than that of the enamel so that in the treatment of patent leather shoes where the toes have been cracked and sand-papered down it has been necessary to coat the entire cap of the toe with refinishing material or if no cap is present to carry the treatment along the entire toe and also along the sides of the vamp as well in order to avoid leaving a line of demarcation between the treated and untreated portions.

By the present invention the scratch or crack can be sand-papered or buffed down and treated with the usual filler and then refinlshed to correspond to the luster of the original surface without the necessity of treating any portion of the leather other than the damaged surface and the surface immediately adjacent thereto. Where scratches or abrasions which do not extend" through the enamel are present this process may be utilized to restore the original finish without the necessity of application of a filler or a varnish or any other material such as that which is ordinarily employed for the purpose aforesaid.

One of the principal advantages of the present process is that any portion of the shoe may be refinished to have its luster correspond to that of the adjacent portions of the shoe without leaving any perceptible line of demarcation between the surface which is treated by the process and that which is not treated, whether the polish of a highly glazed surface is reduced to the lustrous appearance of the enameled leather or a dulled finish is raised to the same luster as that of the original finish.

While the process is primarily designed for the purpose of refinishing parts of leather having an enamel coating which have become damaged the process is equally applicable to putting an original finish upon the leather.

The process may be described generally as a'method of treating leather to produce a lustrous finish which consists in rubbing the surf-ace of the leather with a fibrous frictional material traveling at a high rate of speed and carrying a composition com prising a soft finely granular mineral sub stance intimately mixed with an oleaginous material. The conjoint act-ion of the friction of the applying mechanism and the abrading or cutting produced by the mineral substance with its oleaginous binder upon the enamel and upon the filling, if filling is used, serves to produce the desired luster without leaving any line of demarcation between the original and the restored portions of the surface of the leather.

In the performance of the process suitable mechanism is employed to apply the composition to the surface with the proper degree of friction necessary to raise or reduce the finish of the surface treated to the desired lustrous appearance.

A convenient mechanism for performing the process is illustrated in the accompanying drawings in which,

Figure 1 is a side elevation of the machine.

' Fig. 2 is a vertical sectional view on lines 22 Fig. 1 looking toward the left, the pipe leading to the blower having been omitted, and.

Fig. 3 is a detail view of a bar of the composition employed in the performance of the process. The mechanism illustrated in the accompanying drawing is substantially similar to the usual buffing machinery, any suitable type of which may be employed in the performance of the process.

The machine disclosed herein comprises a base 1 with astandard2rising centrally therefrom and preferably of yoke form, the arms 3 and a of which provide extended bearings 5, 6 for the shaft 7. A plurality of buffing wheels are mounted upon this shaft. Any suitable number of wheels may be used. As shown herein the three wheels 8, 9 and 10 are made of disks of unbleached cotton which are raveled at the periphery and a fourth wheel 11 which desirably is formed of wicking the strands of which. extend radially from the shaft. The wheel 8 preferably is narrower than the wheels 9, 10 and 11, desirably being-about a third of an inch wide, While the Wheels 9, 10 and 11 are approximately an inch wide. By reason of this construction the narrow wheel may be used to reach into narrower spaces such as the vamp of the shoe adjacent the sole and curved instep portion. The composition is applied to two of the wheels only, preferably the wheels 8 and 9, .the other two wheels serving to remove any composition which may adhere to the leather and to bring the same to the lustrous appearance desired. The wheels 9 and 10 which remove the material from the leather and perform the final operations gradually accumulate the composition from the leather so that it is desirable that means he provided by which the disks can be readily removed from the shafts and replaced by new ones while the disks thus removed may be used to replace the composition applying disks when the latter wheels become worn.

In order to accomplish this function the shaft 7 is provided with collars 12, 13 located adjacent the ends of the bearings 5, 6. The buffing wheels 9 and 10 are clamped against these collars by collars or flanges 14, 15 upon or engaged by sleeves 16, 17 which extend nearly to the end of the shaft 7. The sleeves 16, 17 have upon their opposite ends similar collars 18, 19 which engage the sides of the disks 8 and 11 respectively. Collars 20, 21 are clamped against the outer sides of the disks 8, 11 by nuts 22, 23 which are screwed upon the ends of the shaft 7.

When it is desired to remove the buffing wheels at either end it is merely necessary to unscrew the nuts 22 and 23 and slip off the sleeve 11 and the builing wheels which are retained by said nut and sleeve. The shaft is provided intermediate of the bearings 5 and 6 with the usual fast and loose pulleys 24 and 25 which may be driven from any suitable source of power.-

In order to collect and carry away any excess of composition which may be applied and also any debris which may result from the finishing operation, each of the cotton bufiing wheels is provided with a surrounding hood or casing. These hoods may be constructed in any well known manner. As illustrated herein the hoods comprise upper and lower sections, the lower sections preferably comprising two complementary hollow parts 26, 27 having a rearward extension 28 provided with a pipe connection 29 to which a pipe 30 leading to a suitable exhaust fan may be connected.

The upper section may likewise be formed in two complementary parts having flanges 31, 32 by which they may be secured together by rivets or other fastenings. The upper section desirably is provided at its lower end with cars 33 which are pivotally connected to a shaft or stud 3i carried by the lower section so that the upper section may be thrown backwardly to expose the wheel. This is quite essential as it is necessary to rake the cotton bufling wheels quite frequently.

The cotton bufiing wheels should be originally about six inches in diameter and their periphery should be raked or unraveled to the depth of about one half inch and this depth of unraveled buff should be maintained by raking the wheels several times a day when the machine is in continuous operation.

It is found in practice that the process operates most sucessfully when the frictional surface is traveling at a speed of about three thousand feet per minute, consequently the bufiing wheels are driven at substantially two thousand revolutions per minute but thisspeed may be varied within such limits as may be found in practice to produce the best results.

The composition which is used in the performance of this process comprises a soft finely granular mineral substance preferably of a caustic nature intimately mixed with a solid oleaginous material, the composition being sueh that it may be made in stick form as shown in Fig. 3 and applied to the periphery of the buffing wheels by merely resting the end of the stick upon the wheels 8 or The preferred composition which has been found most successful in the performance of this process comprises a mixture of Vienna lime and mutton tallow in the relative proportions of from three to four parts of lime to one part of mutton tallow, the Vienna lime being very finely pulverized and sifted through a sieve of at least 200 mesh to the square inch.

While a mixture of mutton tallow and Vienna lime is the most successful composition now known to me for performing the process it will be understood that my invention comprises. broadly the finely granular caustic mineral substance intimately mixed with a solid oleaginous material. In the performanceoof the process a small amount of the composition is pplied to each of the buiiing wheels 8 and 9 which are rotated at a surface speed of about three thousand feet per minute. If leather having slight imperfections or mars only is to be treated the enameled surface is presented gently to the surface of the cotton bufiing wheel carrying the aforesaid composition until the desired luster is substantially obtained.

The action of the frictional surface together with that of the composition is such that it will restore the enameled leather to its original luster without the necessity of further treatment. It is, however, desirable in the performance of the process not to perform the complete operation upon the bufling wheels which carry the composition but that these bufing wheels shall be used until the desired luster is approximately reached and the leather or portion of leather being treated be then presented to the bufling wheel 10 which will serve to remove any composition which may have adhered to the leather and also substantially to complete the bringing of the treated surface to the desired luster through the small amount this wheel gradually obtains from the first wheel being carried by the shoe or piece of leather treated.

The final buffing wheel which desirably is made of wicking serves merely to insure the complete removal of the composition.

Where the surface of the enamel has been cracked it should be partially or wholly removed from the leather for some distance along the edges of the crack and the usual filler employed in the repair of leather applied. This filler usually comprises a base such as lamp black and an adhesive substance maintained in plastic condition by acetic ether or amylacetate or acetone. This filler may be applied by a brush in successive coats in t e usual manner and permitted to dr between each apphcatlon. The portion t us filled 1n presents a highly use of a soft glazed appearance often showing brush marks, specks of dust, etc. This makes a considerable contrast to the desired lustrous surface of the body of the leather and heretofore it has been found quite impossible to cause it to merge into the lustrous surface of the enameled leather without making a line of demarcation. By treating the filled in portion thus described with the composition applied by a frictional surface traveling at a predetermined rate of speed, preferably about three thousand feet per minute the highly glazed appearance of thefilled in portion is brought down to the luster of the original leather.

The composition when applied by the bufiing wheel at a sufficient rate of speed to produce a predetermined amount of friction will act upon the filler and the enamel immediately adjacent the filler in such a manner as to render the molecular elements of the filler and enamel slightly mobile and will cause them to intermingle homogeneously so that they will present the lustrous surface appearance of the original enamel,

the overlapping edges of the filler and original enamel being so merged into each other that no line of demarcation exists in the refinished enainel. 7

It has been found in practice that if the speed of the frictional material is too great there will be heating or burning of the enamel which will destroy its luster and that if the speed of the frictional surface be too low the filled in portion will not be brought down to the desired lustrous appearance.

The process above described has been very successfully used in the refinishing of enamel or patent leather shoes which have become damaged during manufacture and the process is now being widely used for refinishing shoes.

Under some circumstances it is desirable 7 that the removal of all of the oleaginous and caustic material must be more thoroughly insured. In such case the treated leather may be rubbed off with a suitable solvent which will not at the same time dissolve any of the filler. This however, is not ordinarily necessary.

While the invention has been disclosed herein as applied to the treatment of enameled leather and is designed primarily for use in refinishing shoes, it will be under stood that the process may be utilized for other purposes, for example it is found in practice that by treating leather which has a usual finish other than enamel, the surface may be brought to a lustrous appearance similar to that of enameled leather.

Furthermore the process may be applied to refinishing certain other lustrous surfaces such as fibrous or metallic articles having an enamel finish. The claims, therefore, are

designed to cover the process broadly in any of the many uses to 'hich it may be adapted.

' Having thus described my invention what I claim as new and desire to secure by Letters Patent is;

1. The process of resurfacing enamel which consists in frictionally treating the enamel with a solid oleaginous composition having a finely granular caustic material intimately mixed therein capable of acting when applied with a predetermined amount of friction, to render the molecular elements of said enamel mobile and to produce a homogeneous surface having the lustrous surface of the original enamel.

2. The process of resurfacing enamel which consists in frictionally treating the enamel with a solid oleaginous composition having finely granulated Vienna lime intimately mixed therein and capable of acting when applied with a predetermined amount of friction to render the molecular elements of said. enamel mobile and to produce a homogeneous surface having the lustrous appearance of the original enamel.

3. The process of resurfacing enamel which consists in frictionally treating the enamel with a composition comprising mutton tallow and finely granulated Vienna lime intimately mixed therein and capable of acting when applied with a predetermined amount of friction to render the molecular elements of said enamel mobile and to produce a homogeneous surface having the lustrous appearance of the original enamel.

t. The process of resurfacing damaged enamel which consists in applying to the damaged portion a suitable filler, frictionally treating the filler and adjacent enamel with a solid oleaginous composition having a granular caustic material. intimately mixed therein and capable of acting when applied with a predetermined amount of friction to render the molecular elements of the enamel and filling mobile and to intermingle homogeneously the molecular elements of said filler and enamel whereby the same lustrous appearance is produced upon the prepared portion as that of the original enamel.

5. The process of resurfacing damaged enamel leather which consists in removing the enamel adjacent the damaged portion, applying to the removed portion a filler which has normally a more highly lustrous surface than the surface of the original enamel, then frict-ionally treating the filler and adjacent enamel with a solid oleaginous composition having a granular caustic material intimately mixed therein and capable of acting when applied with a predetermined amount of friction to render the molecular elements of the enamel and the filler mobile and to intermingle homogeneously the molecular elements of the filler and enamel to produce a lustrous surface having the same appearance as that of the original enamel whereby no line of demarcation is exhibited between the original enamel and the filler.

6. A step in the process of treating enameled leather to produce a lustrous finish which consists in rubbing the surface of the leather with a fibrous frictional material t'aveling at speed of about three thousand feet per minute and carrying a composition comprising finely granular Vienna lime intimately mixed with mutton tallow in the proportions of four parts of Vienna lime to one part of mutton tallow.

7. A step in the process of treating enameled leather to produce a. lustrous finish which consists in rubbing the surface thereof with a fibrous frictional material traveling at a rate of about three thousand feet per minute and carrying a solid composition comprising finely granular Vienna. lime intimately mixed with mutton tallow.

8. The process of refinishing damaged enameled leather which consists in removing enamel adjacent the damaged portion, applying a filler thereto, butting the filler and adjacent portions of the enamel with a fibrous frictional material traveling at a speed of about three thousand feet per minute and carrying a composition comprising finely granular Vienna lime intimately mixed with mutton tallow in the proportions of four parts of Vienna lime to one part of mutton tallow.

In testimony whereof; I have signed my name to this specification.

ROLAND L. SMITH. 

